On M-hyponormal weighted shifts

[摘要] Let alpha equivalent to {x(n)}(n=0)(infinity) be a weight sequence and let W, denote the associated unilateral weighted shift on l(2)(Z(+)). In this paper we prove that if alpha is eventually increasing, then W-alpha is M-hyponormal and that if alpha has exactly two subsequential limits such that the larger one is different from the spectral radius of W-alpha then W-alpha is not M-hyponormal. (C) 2003 Elsevier Inc. All rights reserved.

[发布日期] 2003-10-01

[关键词] M-hyponormal operators;unilateral weighted shifts